elasticsearch嵌套聚合问题

{

  "aggs": {

    "3": {

      "sum_bucket": {

        "buckets_path": "3-bucket>3-metric"

      }

    },

    "3-bucket": {

      "terms": {

        "field": "li.keyword",

        "size": 5,

        "order": {

          "_key": "desc"

        }

      },

      "aggs": {

        "3-metric": {

          "max": {

            "field": "cost"

          }

        }

      }

    }

  },

  "size": 0,

  "query": {

    "bool": {

      "must": [

        {

          "range": {

            "x_st": {

              "gte": 1565625600000,

              "lte": 1565711999999,

              "format": "epoch_millis"

            }

          }

        }

      ]

    }

  }